That little gizmo on the top of the ladder is a palm nailer. It took on the difficult task of nailing red oak to the timberframe. It made like a little woodpecker and pecked the nails in.
If you want to read the giddy reviews of happy handymen who have used these, look up "palm nailer" on Amazon.
I'll just say that my carpenter was so impressed with it that he said it would be his next tool purchase.